Spray tank



FIG. 1 is a perspective view of a new and ornamental design for a spraytank;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a first side elevation view thereof;

FIG. 5 is a second side elevation view thereof;

FIG. 6 is top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

CLAIM The ornamental design for a spray tank, as shown and described.